<!--
 * @Author: xiuquanxu
 * @Company: kaochong
 * @Date: 2020-12-16 00:09:34
 * @LastEditors: xiuquanxu
 * @LastEditTime: 2020-12-30 19:03:23
-->
<html>
    <meta charset="utf-8"/>
    <style>
        .d {
            height: 20px;
            margin: 0 10px;
            background-color: white;
        }
        .p {
            width: 500px;
            height: 500px;
            background-color: black;
            display: flex;
            align-items: center;
            justify-content: center;
        }
    </style>
    <body>
        <div class="p">
            <div class="d">
                this is div 1
            </div>
            <div class="d">
                this is div2
            </div>
            <div class="d">
                this is div3
            </div>
            <div class="d">
                this is div4
            </div>
        </div>
    </body>
</html>